* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Human Genetics PowerPoints Notes
Survey
Document related concepts
Gene expression programming wikipedia , lookup
Skewed X-inactivation wikipedia , lookup
Minimal genome wikipedia , lookup
Quantitative trait locus wikipedia , lookup
Biology and consumer behaviour wikipedia , lookup
Neocentromere wikipedia , lookup
Artificial gene synthesis wikipedia , lookup
Genomic imprinting wikipedia , lookup
Gene expression profiling wikipedia , lookup
Dominance (genetics) wikipedia , lookup
Y chromosome wikipedia , lookup
Microevolution wikipedia , lookup
Polycomb Group Proteins and Cancer wikipedia , lookup
Epigenetics of human development wikipedia , lookup
Designer baby wikipedia , lookup
Transcript
Two copies of each autosomal gene affect phenotype (physical). • Mendel studied autosomal gene traits, like hair texture. Autosome – chromosome with genes not related to sex of organism (body cells) Dwarfism and Longevity BIO.B.2.1.1 Describe and/or predict observed patterns of inheritance (i.e., dominant, recessive, co-dominance, incomplete dominance, sex-linked, polygenic, and multiple alleles). • Amniocentesis • Incomplete dominance • Co-dominance • Carrier • Polygenic • Epistatic • Autosomes • Pedigree • Karyotype Several methods help map human chromosomes. • Karyotype - a picture of all chromosomes in a cell. XY • Karyotypes can show changes in chromosomes. – deletion of part of a chromosome or loss of a chromosome – large changes in chromosomes – extra chromosomes or duplication of part of a chromosome Karyotype The arrangement of all the chromosomes found in a cell. Includes: Autosomes: chromosome pairs 1-22 Sex Chromosomes: chromosome pair 23 Female = XX Male = X Y 23rd pair Female sex chromosomes XX Process Box 1: What information can you determine from a karyotype. Use the terms autosomes and sex chromosomes. Amniocentesis A medical technique used to collect the chromosomes of a developing fetus. It is done by inserting a needle into the womb and gathering cells in the amniotic fluid. FEMALE “Autosomes” MALE Sex Chromosomes (they determine male or female) Who determines the sex of the offspring? Father – he can provide an X or Y chromosome Egg X X XX XX X X Body Cell X XX XX XY XY X XY Body Cell Y Y Sperm 1female:1male We were all female • Genes on sex chromosomes are called sex-linked genes. . – Y chromosome - male characteristics . – X chromosome - genes affects many traits. Males can pass on X or Y Females only pass on X East German Olympic team Process Box 2: King Henry VIII is known for being ‘angry’ with his wives and blamed them for not producing a son. Explain why King Henry VIII should have found fault with himself. • Males have an XY genotype. – All of a male’s sex-linked genes are expressed. – Males have no second copies of sex-linked genes – Y chromosome is much smaller Females can carry sex-linked genetic disorders. • Males (XY) express all of their sex linked genes. • Expression of the disorder depends on which parent carries the allele and the sex of the child. X chromosome carries about 1100 genes while the Y carries about 250 Sex-linked disorder: Color Blindness 1. Genetic disorder found on the sex chromosome X 2. Known as a “sex-linked” because its found on chromosome 23 3. Normal Color Vision (N) = Dominant Colorblindness (n) = Recessive 2. Can’t distinguish between colors 3. More boys, than girls, are color blind…..WHY? • Color blindness is a problem in which red or green look like shades of gray or other colors. Jets vs Bills • The gene is carried on the X chromosome and is a recessive trait. XN XNXN = normal female XNXn = female, normal vision (carrier) XNY = normal vision male XnY = color blind male XN Y Xn XNXN XNXn XNY XnY Sex-linked disorder: Color Blindness XN XN Color blind Dad and Normal mother produces…. Two normal sons Xn XN Xn XN Xn Y XN Y XN XN 2 “carrier” daughters (NOT color blind) XN Y Xn XN XN XNXn Normal Dad and Carrier mother produces…. 1 color blind son, 1 normal son 1 “carrier” daughter, 1 normal daughter Y XN Y Xn Y What is the only way to get a color-blind daughter?? Sex-linked disorder: Hemophila 1. Recessive genetic disorder found on the sex chromosome X 2. Disease in which blood doesn’t clot properly. 3. Normal Blood Clotting (N) = Dominant Hemophilia (n) = Recessive Royal family pedigree Rasputin Sex-linked disorder: Hemophila XH XH Affected dad and Normal Mother produces…. Two normal sons Xh XH Xh XH Xh Y XH Y XH 2 “carrier” daughters XH Y Xh Normal Father and Carrier Mother produces…. XH XH XH XH Xh 1 color blind son, 1 normal son 1 “carrier” daughter, 1 normal daughter Y XH Y Xh Y What cross will ALWAYS yield you 100% affected sons? – Carrier – has an allele for as trait or disease that is not expressed. – Carrier does not have disease symptoms but can pass it on to offspring. ___ ___ ___ ___ __ __ ___ __ __ TOP PARENT: A CARRIER MOM: A CARRIER SIDE PARENT: AFFECTED DAD: AFFECTED -Dominant allele disorders are rare. -They affect TWO genotypes -Pure Dominant -Heterozygous Huntington’s disease is an example of a disease caused by a dominant allele. (Danny with Huntington’s Disease) Process Box 3: What does it mean to have a sex-linked trait? Why do men have a greater chance of being ‘affected’ with certain sex-linked traits/disorders? Process Box 4: Is this a “sex-linked” trait or an “autosomal trait” if the gene is found on … a. b. c. d. Chromosome 12 and the gene is dominant? Chromosome 23 and the gene is dominant? On the X chromosome and it is dominant? On the X chromosome and it is recessive? Do Now • In a family, the father does Not have hemophilia and the mother is a carrier. What is the chance that they will have a child with hemophilia? XN y XN Xn XNXN XNXn XNy Xny 1XNXN : 1XNXn : 1XNy : 1Xny 1 normal female 1 normal ‘carrier’ female 1 normal male 1 hemophiliac male 25% chance of having a child effected with hemophilia The child WILL ALWAYS BE A MALE!!!! 50/50 chance for a male child to have hemophilia • Some traits are neither totally dominant nor totally recessive. • Incomplete dominance - when neither gene is totally dominant to the other - Heterozygous phenotype is intermediate between the two homozygous phenotypes – Example: White flowers and red flowers produce pink flowers Incomplete Dominance X Straight Curly Pink There is a third color that exists in the heterozygous type. It’s a. mixture between the two homozygous types. Incomplete Dominance Incomplete Dominance Incomplete Dominance Incomplete dominance • Codominant - alleles will both be completely expressed. – Codominant alleles are neither dominant nor recessive. – The ABO blood types result from codominant alleles. Example – red and white flower produce a flower with BOTH colors • Many genes have more than two alleles. Co-dominance Heterozygous type shows BOTH phenotypes exist TOGETHER Co-dominance Co-dominance Co-dominance Process Box 5: Describe the difference between co-dominance and incomplete dominance. Write/or draw an example of codominance and incomplete dominance. Incomplete: INBETWEEN BLEND Codominant: COEXIST By the results, determine if the traits code for: complete dominance, incomplete dominance, or codominance: Brown x White = Brown ___________________ Tall x Short = Medium___________________ Blood A x Blood B = AB ___________________ Sickle Cell Anemia • Disease in which the body makes sickle-shaped red blood cells. Sickle-shaped cells don’t move easily through your blood vessels. They’re stiff and sticky and tend to form clumps and get stuck in the blood vessels •The disorder is found on chromosome 11. and is therefore not sex-linked. • The Oxygen carrying hemoglobin can not carry oxygen as efficiently and the odd-shaped cells can easily clot and break. Fatigue, pain, and organ failure due to lack of oxygen supply are common symptoms of sickle cell anemia. • It is common in the African community Actual blood cells Sickle Cell Anemia Codominance Practice • Genes for blood cells: • R = Round blood cells • R’ = Sickle Cells R R’ Genotypes for blood cells RR = normal blood R RR’ = some sickle cells, some normal cells R’R’ = has sickle cell anemia Tebow touchdown R’ RR RR’ RR’ R’R’ Complete the following crosses, Report the genotypes and phenotypes of the offspring R = round blood cell R’ = sickle shape RR: Round cells RR’ = sickle cell trait R’R’: sickle cell anemia Mixed Cells x Hybrid ---------- x ---------R’ R Round Blood Cells x Hybrid ---------- x ---------EXPECTED R R EXPECTED R’ R’ R’ R RESULTS 1 sickle cell anemia -------------------------- R’ R’ R R’ R R R’ R RR 2 mixed cells -------------------------1 normal cells -------------------------- R RR RR R’ Sickle Cell Anemia x Pure Round ---------- x ---------- R’ R’ R R’ R R’ R R R’ R R’ R EXPECTED RESULTS 4 mixed cells -------------------------- 2-------------------------normal cells -------------------------- All Round Cells x All Sickle Cells ---------- x ---------- R’ R -------------------------- -------------------------- RESULTS 2-------------------------mixed cells R R’ R R’ R’ R EXPECTED RESULTS 4-------------------------mixed cells -------------------------- R’ R R’ R -------------------------- WRITTEN CONCLUSION • • • • • INTRO VARIABLE DATA ANALYSIS EXTENSION 1. Blood Type 4 different blood types • there are _________________________ Blood Type Genes Blood Type A IAIA or IAi Blood Type B IBIB or IBi Blood Type AB IAIB Blood Type O ii How many alleles for blood are there? 3 How many blood types are there? 4 • Hypothesis: • What crosses will produce sickle cell trait versus sickle cell anemia Which blood types are compatible for transfusion?? Yes or No ? O B A AB B Yes A No AB Yes A No Yes O AB IB IB IA IA IA IB IAIB I AIB IAIB 4___________ type AB blood IB ___________ ___________ i IA i I AIB IBi IAi ii IA IB IA i IBi 1-AB blood 1-hetero A blood ___________ 1-hetero B blood 1-pure O blood ___________ ___________ IA IA IA IA IB IA IB IA i IB IAIB IBIB i i I Ai IAi ii ii i 1-pure A blood ___________ 2-AB blood i 1-pure B blood ___________ IA ___________ 2-hetero A blood i 2O blood ___________ IA i IBi IA i IA IA IAi 2-hetero A blood ___________ 2-heteroB blood ___________ IAi ii ___________ 2-hetero A blood ___________ 1- O blood IB IB IA IA IA IB IAIB I AIB IA 4___________ type AB blood ___________ ___________ ___________ IAIB IA IB ___________ IB ___________ A mother with type O crossed with a father with heterozygous type A i i i IAi IAi ii ii IB ___________ i ___________ An AB mother with an O father IA IB IA IA i i IAi IBi i IAi IBi 2-hetero A blood ___________ 2-heteroB blood ___________ Two heterozygous type A’s crossed IA IA 2-hetero A blood ___________ 2- O blood i ___________ IA IA IAi i IAi ii ___________ 2-hetero A blood 1- O blood ___________ Blood type statistics… • If there are 100 people in the room: 39 will be O+ 7 will be O34 will be A+ 6 will be A9 will be B+ 2 will be B3 will be AB+ and only 1 in 200 will be ABNote: The + and – is the presence (or absence) of a third antigen (Rh). • Polygenic traits are produced by two or more genes. Order of dominance: brown > green > blue. • Epistatic gene - can interfere with the expression of all other genes. Mice have 5 genes that control fur color. 2 genes for general color 1 for shading 1 for spots 1 epistatic gene for color that overrrules all other genes • Phenotype is a combination of genotype and environment. • The sex of sea turtles depends on both genes and the environment. Warm eggs develop into females • Height is an example of a phenotype strongly affected by the environmental factors such as early nutrition and health care. Process Box 6: Using the words below, make two list that you would associate with the following types of genes: Epistatic Polygenic Many Over-ride Interaction Several Multiple Dominant Range One Control Rule Boss Various Albinism Eye color • Linked genes are not inherited together every time. • Chromosomes exchange homologous genes during meiosis. Crossing over – 7:00 Linkage maps – map of location of genes on a chromosome. • The closer together two genes are, the more likely they will be inherited together. • Cross-over frequencies are related to distances between genes. • Cross-over frequencies can be converted into map units. – gene A and gene B cross over 6.0 percent of the time – gene B and gene C cross over 12.5 percent of the time – gene A and gene C cross over 18.5 percent of the time Pedigree - chart for tracing genes in a family. • Phenotypes are used to infer genotypes on a pedigree. • Autosomal genes show different patterns on a pedigree than sex-linked genes. Widow’s peak: W = widow’s peak w = non widow’s peak • If the phenotype is more common in males, the gene is likely sex-linked. Colorblindness: M = normal vision m = colorblindness Process Box 7: In a pedigree, what shape represents the male? You can gather useful information from studying pedigree diagrams. List the ‘hints’ that help you determine ways that you can determine if it is sex-linked or autosomal.